Production of S-acetoin from diacetyl by Escherichia coli transformant cells that express the diacetyl reductase gene of Paenibacillus polymyxa ZJ-9

S-acetoin (S-AC) is an important four-carbon chiral compound that has unique industrial applications in the asymmetric synthesis of valuable chiral specialty chemicals. However, previous studies showed that the usually low yield and optical purity of S-AC as well as the very high substrate cost have hindered the application of this compound. In the current work, a gene encoding diacetyl reductase (DAR) from a Paenibacillus polymyxa strain ZJ-9 was cloned and expressed in Escherichia coli. Whole cells of the recombinant E.coli were used to produce S-AC from diacetyl (DA). Under optimal conditions, S-AC with high optical purity (purity >999%) was obtained with a yield of 135024 and 394 +/- 038gl(-1) under batch and fed-batch culture conditions, respectively. This process featured the biotransformation of DA into S-AC using whole cells of engineered E.coli. The result is a considerable increase in the yield and optical purity of S-AC, which in turn facilitated the practical application of the compound. Significance and Impact of the StudyThis study demonstrated a highly efficient new method to produce S-acetoin with higher than 999% optical purity from diacetyl using whole cells of engineered Escherichia coli. It will therefore decrease the production cost of S-acetoin and highlight its application in asymmetric synthesis of highly valuable chiral compounds.